Senator Sam Brownback rolls into the You Choose '08 Spotlight this week from his campaign bus in Iowa. Zipping past rural countryside, the Republican from Kansas talks about growing up on a farm and his "pro-life, whole-life" message.

Brownback plans to answer your questions straight from the campaign trail this week, so upload your video response and keep your eyes peeled to his YouTube channel for more videos.

Over in the Democratic race for the nomination, Senator Joe Biden released four different videos this week addressing those who responded to his Spotlight video about energy independence. Peering over a laptop and addressing users by name, Biden expounds further on an issue that he's made central to his campaign.

Don't forget that you can ask Biden and all the other Democratic candidates questions which may be broadcast and answered LIVE on CNN on July 23. Submit your videos here for the chance to be part of the first-ever user-generated presidential debate!